goodbye blog hello exams

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well my biochem blogging has come and end . 😦  hmmm it was fun while it lasted . i learnt so much from my other peers  and fellow classmates blogs . Their materials posted would serve as additional material for me to utilize while studying . For example if i dont understand a topic clearly i could simple check through some blogs and seek assistance . Thank you sir for this educational and fun assignment by far the most unique project i have ever done . Good luck to everyone in their upcomin exams and may god shower his choicest blessings upon you all . byeeeee

EXAMS ARE NEAR WE SHOULD CARE !!!! study tips for biochem :)

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Biochemistry is a notorious course for demanding a high-volume of information in a short amount of time. However, there are studying methods to assist students in learning efficiently and effectively. I have studied and interviewed groups of medical and science students that have mastered their course work. It is true that there are specific and detailed guidelines that these students adhere to and credit for their academic success. The successful student must excel in visualizing relationships, memorizing facts, and reciting complex metabolic reactions of the human body. With some time and applying these strategies and tips from past honor students ofBiochemistry, you will greatly improve your academic performance.Image

Study Skill #1 – Do NOT procrastinate. The most obvious, and yet least followed advice by students. Biochemistry is a high-volume course that progresses and builds its concepts on the fundamentals. Moreover, many pathways and reactions require memorization and must be acquired over time. The last thing you want to do is cram for this course.

Study Skill #2 – Know the terminology and nomenclature, it will make things much easier down the road. An enzyme or protein will often have its function built into its name. Take Protein Kinase A for example. As a member of the Kinases, it will almost always add a phosphate group to its substrate. Or, take Alcohol Dehydrogenase, structures that are Dehydrogenases always oxidize a substrate. In this case, it oxidizes alcohols into aldehydes and ketones. Once you get this down, you will begin to recognize names and automatically correlate them with a specific function.

Study Skill #3 – Start with the big picture. There is no doubt that you will have to memorize multi-step metabolic pathways. The best way to do this is to start with the easy steps and understand the overall flow of the reaction. First, write only the substrates and products in order. Do this repeatedly, until it is memorized. Then add the enzymes. Then continue to add co-factors and by-products. If necessary, label each as an exer- or endergonic reaction. Use the nomenclature to help you remember what is going on in each step. For example, Phosphofructokinase-1 – adds a phosphate group (phospho-kinase) to the molecule fructose (-fructo-) at the first position (-1). By breaking down the pathways and focusing on the terminology it will greatly speed up your ability to memorize them.

Study Skill #4 – Buy a dry erase board. Use this to memorize the pathways and any other reactions you have to know. There are no short-cuts, but writing things out reinforces them in your memory. It tends to be much more efficient than staring and reciting from your textbook.

Study Skill #5 – Know the purpose of a reaction. Take the Bohr Effect for example. An increase in [H+] (decrease in pH), CO2, temperature, and 2,3-BPG all occur in active skeletal muscle. They also all encourage O2 release from hemoglobin. This makes sense if you think that working muscle is metabolic tissue and needs oxygen to survive. Incorporating the larger concept will also allow you to predict the flow of reactions in other situations throughout the body.

Study Skill #6 – Stare at the graphs and plots. These questions are virtually freebies on exams because all the information you need to solve them is included. Know what the x- and y-intercept, the slope, and the area under the graph represent. Know what makes the graphed line move to the right or left. You will absolutely be asked about the Michaelis-Menten graph and the Hemoglobin dissociation curve – these are staples ofbiochemistry.

Study Skill #7 – Seek to understand first, and then memorize. Like many other courses, biochemistry can be overwhelming at first. There is no easy way to memorize every amino acid or metabolic reaction. But students always claim that if they take the time to first get the concept down, the memorizing is not as difficult as it once seemed. Stay focused, break it down into small steps, and practice.

nucleic acids and its structures

DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are polymers of nucleotides linked in a chain through phosphodiester bonds. In biological systems, they serve as information-carrying molecules or, in the case of some RNA molecules, catalysts. This brief review will focus on aspects of structure of particular importance in manipulating DNA.

Bases, Nucleosides and Nucleotides

Nucleotides are the building blocks of all nucleic acids. Nucleotides have a distinctive structure composed of three components covalently bound together:

  • a nitrogen-containing “base” – either a pyrimidine (one ring) or purine (two rings)
  • a 5-carbon sugar – ribose or deoxyribose
  • a phosphate group

The combination of a base and sugar is called a nucleoside. Nucleotides also exist in activated forms containing two or three phosphates, called nucleotide diphosphates or triphosphates. If the sugar in a nucleotide is deoxyribose, the nucleotide is called a deoxynucleotide; if the sugar is ribose, the term ribonucleotide is used.

The structure of a nucleotide is depicted below. The structure on the left – deoxyguanosine – depicts the base, sugar and phosphate moieties. In comparison, the structure on the right has an extra hydroxyl group on the 2′ carbon of ribose, making it a ribonucleotide – riboguanosine or just guanosine.

In the right-hand figure, note also the 5′ and 3′ carbons on ribose (or deoxyribose) – understanding this concept and nomenclature is critical to understanding polarity of nucleic acids, as discussed below. The 5′ carbon has an attached phosphate group, while the 3′ carbon has a hydroxyl group.

There are five common bases, and four are generally represented in either DNA or RNA. Those bases and their corresponding nucleosides are described in the following table:

Abbr. Base Nucleoside Nucleic Acid
A Adenine deoxyadenosine DNA
adenosine RNA
G Guanine deoxyguanosine DNA
guanosine RNA
C Cytosine deoxycytidine DNA
cytidine RNA
T Thymine deoxythymidine (thymidine) DNA
U Uracil uridine RNA

Another useful way to categorize nucleotide bases is as purines (A and G) versus pyrimidines(C, T and U). Although committing this to memory is often difficult, the importance is that in double-stranded nucleic acids, base pairs are always formed between a purine and a pyrimidine.

Nucleic Acids

DNA and RNA are synthesized in cells by DNA polymerases and RNA polymerases. Short fragments of nucleic acids also are commonly produced without enzymes by oligonucleotide synthesizers. In all cases, the process involves forming phosphodiester bonds between the 3′ carbon of one nucleotide and the 5′ carbon of another nucleotide. This leads to formation of the so-called “sugar-phosphate backbone”, from which the bases project.

A key feature of all nucleic acids is that they have two distinctive ends: the 5′ (5-prime) and 3′ (3-prime) ends. This terminology refers to the 5′ and 3′ carbons on the sugar. For both DNA (shown above) and RNA, the 5′ end bears a phosphate, and the 3′ end a hydroxyl group.

Another important concept in nucleic acid structure is that DNA and RNA polymerases add nucleotides to the 3′ end of the previously incorporated base.Another way to put this is that nucleic acids are synthesized in a 5′ to 3′ direction.

Base Pairing and Double Stranded Nucleic Acids

Most DNA exists in the famous form of a double helix, in which two linear strands of DNA are wound around one another. The major force promoting formation of this helix is complementary base pairing: A’s form hydrogen bonds with T’s (or U’s in RNA), and G’s form hydrogen bonds with C’s. If we mix two ATGC’s together, the following duplex will form:

Examine the figure above and note two very important features:

  • The two strands of DNA are arranged antiparallel to one another: viewed from left to right the “top” strand is aligned 5′ to 3′, while the “bottom” strand is aligned 3′ to 5′. This is always the case for duplex nucleic acids.
  • G-C base pairs have 3 hydrogen bonds, whereas A-T base pairs have 2 hydrogen bonds: one consequence of this disparity is that it takes more energy (e.g. a higher temperature) to disrupt GC-rich DNA than AT-rich DNA.

The figures above fail to impart any appreciation of the three-dimensional structure of DNA. This deficiency can be rectified to some extent by viewing and manipulating a 3-D model of duplex DNA.

What about double stranded RNA? RNAs are usually single stranded, but many RNA molecules have secondary structure in which intramolecular loops are formed by complementary base pairing. A simple example of this is shown in the figure to the right, and much more extensive and complex examples are known. Base pairing in RNA follows exactly the same principles as with DNA: the two regions involved in duplex formation are antiparallel to one another, and the base pairs that form are A-U and G-C.

OK, what about RNA-DNA hybrids? Can they form? The answer is yes. Complementary sequences of RNA and DNA readily anneal with one another to form duplexes. In fact, RNA-DNA hybrids are more stable than the corresponding DNA-DNA and RNA-RNA duplexes.

Proteins are complex, organic compounds composed of many amino acids linked together through peptide bonds and cross-linked between chains by sulfhydryl bonds, hydrogen bonds and van der Waals forces. There is a greater diversity of chemical composition in proteins than in any other group of biologically active compounds. The proteins in the various animal and plant cells confer on these tissues their biological specificity.Image

Proteins can be classified as:

(a) Simple proteins. On hydrolysis they yield only the amino acids and occasional small carbohydrate compounds. Examples are: albumins, globulins, glutelins, albuminoids, histones and protamines.

(b) Conjugated proteins. These are simple proteins combined with some non-protein material in the body. Examples are: nucleoproteins, glycoproteins, phosphoproteins, haemoglobins and lecithoproteins.

(c) Derived proteins. These are proteins derived from simple or conjugated proteins by physical or chemical means. Examples are: denatured proteins and peptides.

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 Structure

The potential configuration of protein molecules is so complex that many types of protein molecules can be constructed and are found in biological materials with different physical characteristics. Globular proteins are found in blood and tissue fluids in amorphous globular form with very thin or non-existent membranes. Collagenous proteins are found in connective tissue such as skin or cell membranes. Fibrous proteins are found in hair, muscle and connective tissue. Crystalline proteins are exemplified by the lens of the eye and similar tissues. Enzymes are proteins with specific chemical functions and mediate most of the physiological processes of life. Several small polypeptides act as hormones in tissue systems controlling different chemical or physiological processes. Muscle protein is made of several forms of polypeptides that allow muscular contraction and relaxation for physical movement.

 Structure

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Essential amino acids
Humans can produce 10 of the 20 amino acids. The others must be supplied in the food. Failure to obtain enough of even 1 of the 10 essential amino acids, those that we cannot make, results in degradation of the body’s proteins—muscle and so forth—to obtain the one amino acid that is needed. Unlike fat and starch, the human body does not store excess amino acids for later use—the amino acids must be in the food every day.

The 10 amino acids that we can produce are alanine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine and tyrosine. Tyrosine is produced from phenylalanine, so if the diet is deficient in phenylalanine, tyrosine will be required as well. The essential amino acids are arginine (required for the young, but not for adults), histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. These amino acids are required in the diet. Plants, of course, must be able to make all the amino acids. Humans, on the other hand, do not have all the the enzymes required for the biosynthesis of all of the amino acids.

proteins!!! yummy in my tummy

Biochem Ronell

Hi every one my name is ronell bridgemohan everyone knows me by my nickname potter . I am 22 years old and i attend uwi st agustine . I attended naparima college for 7 years . I am  currently perusing my bsc in Biology and minors biotechnology and environmental and natural resource management .  My hobbies are reading , watching movies , kayaking , sailing , hiking , swimming , football , badminton and cooking . i love to cook and experiment in the kitchen . This is my blog hope its helpful and u enjoy it thank you 🙂